Question

Tom buys some shirts for $15 each. He has a coupon for $9 dollars off the total price. If he pays $36, how many shirts, s , did he buy

Answer 1

We have to find how many shirts (s) he has bought.

We know that each shirt costs $15, so the total cost of the shirts should be 15*s.

If we substract the discount, we have the total final cost C as:

`C=15\cdot s-9`

If we know that this total cost was $36, we can find the number of shirts as:

`\begin{gathered} C=36 \\ 15s-9=36 \\ 15s=36+9 \\ 15s=45 \\ s=(45)/(15) \\ s=3 \end{gathered}`

Answer: He bought 3 shirts (s = 3).